A device for preparing a phosphogypsum-based foamed material

Abstract

The utility model relates to a kind of phosphogypsum-based foam material preparation device, belong to phosphogypsum resource utilization technical field. Including raw material pretreatment system, foaming preparation system, forming system and solidification curing system. Through high-speed stirring foaming machine adopts adjustable angle stirring blade to combine steam injection technology, realize the accurate control of foaming degree and cell structure;Through continuous casting forming cooperates multi-section gradient curing process, improve production efficiency and product quality. To solve the problem of low utilization rate, unstable foaming quality, insufficient production efficiency and many artificial intervention in prior art, realize the large-scale, continuous and high-value utilization of phosphogypsum, with significant economic benefits and environmental protection significance.

Description

Technical Field

[0001] This utility model belongs to the technical field of phosphogypsum resource utilization, specifically relating to a phosphogypsum-based foaming material preparation device. Background Technology

[0002] Phosphogypsum is an industrial byproduct generated during the wet-process phosphoric acid production process, producing approximately 4-5 tons of phosphogypsum for every ton of phosphoric acid produced. my country's annual phosphogypsum production exceeds 80 million tons, but the comprehensive utilization rate is only about 40%. The long-term stockpiling of large quantities of phosphogypsum not only occupies land resources but also poses environmental pollution risks. Therefore, the resource utilization of phosphogypsum has become a crucial issue that urgently needs to be addressed.

[0003] Phosphogypsum, whose main component is calcium sulfate dihydrate (CaSO4·2H2O), possesses excellent cementing properties and lightweighting potential, making it a high-quality raw material for preparing lightweight building materials. Foamed materials, due to their lightweight, thermal insulation, and sound insulation properties, are in high demand in the field of building energy conservation, and have a broad market prospect. Preparing phosphogypsum into foamed materials can both realize the resource utilization of waste and meet the needs of green building materials development.

[0004] The main methods for preparing phosphogypsum-based foamed materials include: (1) chemical foaming method, which uses chemical foaming agents such as hydrogen peroxide and aluminum powder, but there are problems such as uneven distribution of foaming agents and difficulty in controlling the cell structure; (2) physical foaming method, which introduces air through mechanical stirring, but the foaming effect is limited and the density control accuracy is low; (3) biological foaming method, which uses microorganisms to produce gas, but the process is complex and the production cycle is long.

[0005] Existing foaming equipment is mostly intermittent, with low automation and poor product quality stability. The blade angle of the mixing equipment is fixed, making it impossible to adjust the foaming effect according to different formula requirements; the curing process uses natural curing or simple heating, resulting in imprecise temperature control that affects product strength and performance; and it lacks continuous production capabilities, leading to low production efficiency and difficulty in meeting the needs of large-scale industrial production.

[0006] Therefore, developing a phosphogypsum-based foaming material preparation device with a reasonable structure, advanced technology, and the ability to achieve continuous production is of great significance for improving the comprehensive utilization rate of phosphogypsum and promoting the development of the green building materials industry. Summary of the Invention

[0007] In view of the problems existing in the prior art, the purpose of this utility model is to provide a device for preparing phosphogypsum-based foaming materials, so as to realize the large-scale, continuous and high-value utilization of phosphogypsum, which has significant economic benefits and environmental protection significance.

[0008] To achieve the above objectives, this utility model provides a phosphogypsum-based foaming material preparation device, comprising a raw material pretreatment system, a foaming preparation system, a molding system, and a curing system. The raw material pretreatment system includes a phosphogypsum storage silo, a screw feeder, a vibrating screen, a rotary dryer, and a weighing feeder connected in sequence. The foaming preparation system includes a high-speed stirring foaming machine, a steam generator, and a foaming agent metering tank. The molding system includes a continuous casting device and a vibration leveling device. The curing system includes a tunnel curing kiln, a track conveying system, and a curing vehicle.

[0009] The phosphogypsum raw material first enters the vibrating screen via a screw feeder from the storage silo. The vibrating screen adopts a double-layer screen structure to remove impurities and ensure uniform particle size of the raw material. The phosphogypsum after screening enters the rotary dryer. The dryer is equipped with lifting plates and uses hot air at 120-150℃ to dry the phosphogypsum, controlling the moisture content to below 2%. After drying, the phosphogypsum is accurately weighed by a weighing feeder and then enters the high-speed mixing and foaming machine.

[0010] The high-speed stirring foaming machine (6) consists of a stirring tank, a main stirring shaft, and an adjustable angle blade assembly. The blade angle can be adjusted within the range of 15°-45°, and the main stirring shaft speed can be adjusted to 800-1500 rpm. The stirring tank is equipped with an annular steam distribution ring with 8-12 nozzles evenly distributed. The steam pressure is controlled at 0.3-0.8 MPa to regulate the degree of foaming and the cell structure. The foaming agent metering tank injects foaming agent into the tangential direction of the mixer through a metering pump to achieve uniform foaming.

[0011] The continuous casting device includes a casting hopper, an adjustable casting nozzle, a forming conveyor belt, and a side forming plate. The opening height of the casting nozzle is adjustable from 5 to 50 mm to control the product thickness, and the side forming plate is hydraulically adjusted to control the product width. A vibration leveling device is installed above the conveyor belt with an amplitude of 2-8 mm and a frequency of 25-50 Hz to eliminate surface unevenness during the casting process.

[0012] The tunnel-type curing kiln is 20-50m long and is divided into four temperature control zones: preheating zone, heating zone, constant temperature zone, and cooling zone, to achieve gradient curing. A track conveying system is laid inside the kiln, and the curing vehicle carries the product and moves continuously inside the kiln. The curing temperature is 45-65℃ and the humidity is 80-90%.

[0013] Preferably, the adjustable angle blade assembly has 3-4 layers of blades, with 3-6 blades in each layer. By adjusting the blade angle, it can adapt to the foaming requirements of different formulations and improve the control precision of the foaming effect.

[0014] Preferably, the steam distribution ring adopts an annular pipe structure, and the steam nozzles are arranged at equal intervals to ensure that the steam is evenly distributed in the mixing tank and avoid local overheating that could affect product quality.

[0015] Preferably, the tunnel-type curing kiln has steam pipes arranged along its length at intervals of 2-3m, and the top of the kiln is equipped with a dehumidification port and a regulating valve to achieve precise control of temperature and humidity.

[0016] Preferably, the rotary dryer is equipped with lifting plates inside the cylinder, the hot air temperature is controlled at 120-150℃, the moisture content of the discharged phosphogypsum is ≤2%, and the feeding accuracy of the weighing feeder is ±2%.

[0017] Preferably, the device adopts a continuous production design, with each system connected by pipelines, conveyor belts and track systems to achieve fully automated production from raw material input to product output.

[0018] Compared with existing technologies, the advantages of this utility model are: 1. By adopting adjustable-angle stirring blades combined with steam injection technology, precise control of foaming degree and cell structure is achieved, significantly improving product quality stability; 2. The equipment adopts a continuous production design, which increases production efficiency by 2-3 times compared with traditional intermittent equipment, meeting the needs of large-scale industrial production; 3. Multi-stage gradient curing process replaces traditional natural curing, shortening the curing cycle by more than 50% and improving product strength and performance; 4. High degree of integration, small footprint, high level of automation, reducing labor costs and operational difficulty; 5. Achieve high-value utilization of phosphogypsum industrial waste; the density of the prepared lightweight foamed material can be controlled at 300-800 kg / m³, and it has good thermal insulation performance. 6. The entire system operates stably, consumes little energy, is easy to maintain, and has good engineering adaptability and economic benefits. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the connection of the device of this utility model.

[0020] Figure 2 This is a flowchart illustrating the operation of this utility model.

[0021] Figure 3 This is an isometric drawing of the high-speed mixing and foaming machine of this utility model.

[0022] Figure 4 This is an exploded view of the high-speed mixing and foaming machine of this utility model.

[0023] Figure 5 This is a top view of the high-speed mixing and foaming machine of this utility model.

[0024] Figure 6 This is a frontal sectional view of the high-speed mixing and foaming machine of this utility model.

[0025] In the attached diagram, the following are the reference numerals: 1, phosphogypsum storage silo; 2, screw feeder; 3, vibrating screen; 4, rotary dryer; 5, weighing feeder; 6, high-speed mixing and foaming machine; 7, steam generator; 8, foaming agent metering tank; 9, continuous casting device; 10, vibrating leveling device; 11, tunnel curing kiln; 12, track conveying system; 13, curing vehicle; 61, mixing tank; 62, main mixing shaft; 63, adjustable angle blade assembly; 64, annular steam distribution ring. Detailed Implementation

[0026] To make the objectives, technical solutions, and beneficial effects of this utility model clearer, the embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0027] Example: like Figure 1-6 As shown, this utility model provides a phosphogypsum-based foaming material preparation device, including a phosphogypsum storage silo 1, a screw feeder 2, a vibrating screen 3, a rotary dryer 4, a weighing feeder 5, a high-speed mixing foaming machine 6, a steam generator 7, a foaming agent metering tank 8, a continuous casting device 9, a vibrating leveling device 10, a tunnel curing kiln 11, a track conveying system 12, and a curing vehicle 13.

[0028] The phosphogypsum storage silo 1 is a cylindrical structure with a volume of 50-200 m³, and has a 60° conical discharge port at the bottom, which is connected to the screw feeder 2. The screw feeder 2 uses stainless steel screw blades with a pitch of 200-300 mm and an adjustable speed of 2-10 rpm, and is used to quantitatively convey phosphogypsum to the vibrating screen 3.

[0029] Vibrating screen 3 adopts a double-layer screen structure, with an upper screen hole diameter of 5mm and a lower screen hole diameter of 2mm. The amplitude is 5-8mm and the frequency is 20-30Hz, effectively removing large particulate impurities and lumps from phosphogypsum. The sieving phosphogypsum enters the rotary dryer 4 via a conveyor belt.

[0030] The rotary dryer 4 is a rotary cylindrical structure with a diameter of 1.5-3.0m and a length of 8-15m. It is equipped with lifting plates inside, and the hot air temperature is controlled at 120-150℃ with a residence time of 30-60 minutes, reducing the moisture content of the phosphogypsum to below 2%. The dried phosphogypsum is then precisely metered by a weighing feeder 5 with a feeding accuracy of ±2% and an adjustable flow rate of 1-10t / h.

[0031] The weighing feeder 5 conveys a measured amount of phosphogypsum to the high-speed mixing and foaming machine 6. The high-speed mixing and foaming machine 6 is the core equipment; the mixing tank is cylindrical, with a diameter of 1.2-2.0m and a height of 1.5-2.5m, made of 304 stainless steel. The main mixing shaft is vertically mounted and equipped with an adjustable-angle blade assembly, containing 3-4 layers of blades, with 3-6 blades per layer. The blade angle can be adjusted within the range of 15°-45°, and the rotation speed is adjustable from 800-1500 rpm.

[0032] The mixing tank 6 is equipped with an annular steam distribution ring. The annular pipe has an inner diameter of 50-80mm and 8-12 nozzles with a diameter of 2-5mm are evenly distributed. The steam generator 7 is connected to the steam distribution ring through a pipe. The steam generator has a vertical structure, a steam output of 500-2000kg / h, and an operating pressure of 0.3-0.8MPa. It injects steam into the mixing tank to control the degree of foaming.

[0033] The foaming agent metering tank has a capacity of 50-200L, is made of stainless steel, and has a bottom-mounted pump to inject the foaming agent tangentially into the mixer through a pipeline. Commonly used foaming agents are hydrogen peroxide, aluminum powder, or composite foaming agents, and the addition amount is 0.1-0.5% of the phosphogypsum mass.

[0034] The foamed slurry flows from the bottom outlet of the mixing and foaming machine 6 into the continuous casting device 9. The continuous casting device 9 includes a V-shaped casting hopper with an adjustable bottom width of 200-800mm and an adjustable casting nozzle opening height of 5-50mm to control product thickness. The forming conveyor belt uses a steel wire mesh belt with a width of 1-3m, a length of 10-30m, and an adjustable speed of 0.5-3m / min. The side forming plates are adjusted via a hydraulic system to control the product width.

[0035] After molding, the foamed material is processed by a vibration leveling device 10. The vibration leveling device is set above the conveyor belt with an amplitude of 2-8mm and a frequency of 25-50Hz, which effectively eliminates surface unevenness and internal air bubbles generated during the casting process.

[0036] The leveled products enter the tunnel-type curing kiln 11 via the track conveyor system 12. The tunnel-type curing kiln 11 is a brick-concrete structure, 20-50m long, 2-4m wide, and 2-3m high, divided into four temperature control zones: preheating zone (30-40℃), heating zone (40-55℃), constant temperature zone (55-65℃), and cooling zone (65-45℃). Steam pipes are arranged along the length of the kiln body at 2-3m intervals, and a humidity exhaust port with regulating valve is installed at the top to control humidity at 80-90%.

[0037] The track conveying system 12 is laid inside the curing kiln, using a steel rail structure with a track gauge of 600-1000mm. The curing cart 13 is a stainless steel pallet structure, with dimensions matching the product, capable of bearing 500-2000kg. It moves on the track via electric push rods or chain drive, with a conveying speed of 0.5-2m / min.

[0038] Work process: I. Working process of the complete set of utility model devices Phosphogypsum raw material is quantitatively fed from storage silo 1 via screw feeder 2, and after impurities are removed by vibrating screen 3, it enters rotary dryer 4 to dry to a moisture content of ≤2%. The dried phosphogypsum is precisely metered by weighing feeder 5 and then enters high-speed mixing foaming machine 6. Simultaneously, a quantitative amount of foaming agent and appropriate amount of water are added through foaming agent metering tank 8. Under the high-speed stirring of adjustable-angle blades, the raw material and foaming agent are thoroughly mixed. Steam provided by steam generator 7 is evenly injected through distribution ring to form a stable foamed slurry. The foamed slurry is molded into boards or blocks of the required specifications by continuous casting device 9. After surface treatment by vibrating leveling device 10, it is transported by track conveying system 12 to curing cart 13 into tunnel curing kiln 11 for gradient curing, ultimately producing lightweight phosphogypsum foamed material with a density of 300-800 kg / m³.

[0039] II. Working process of the core component, the high-speed mixing and foaming machine The high-temperature, high-pressure steam generated by the vertical steam generator 7 is transported to the annular steam distribution ring 64 through a sealed pipeline, and then evenly sprayed into the mixing tank 61 through the nozzles of the distribution ring. At the same time, the main stirring shaft 62 drives the adjustable angle blade assembly 63 to rotate at high speed, applying shearing and mixing forces to the material to be foamed in the tank, causing the material to form a flow vortex. Under the action of the vortex, the steam comes into full contact with the material, and the activity of the material molecules increases after heating. The steam bubbles are sheared and dispersed into fine foam. By adjusting the blade angle (controlling the material flow intensity), the main shaft speed (controlling the stirring force), and the steam pressure / flow rate (controlling the steam input), the foam formation speed and fineness can be adjusted in real time, ultimately achieving a controllable material foaming effect.

[0040] In summary, this invention achieves precise control of the foaming effect through the combination of adjustable-angle stirring blades and steam injection technology; the continuous production design significantly improves production efficiency; and the multi-stage gradient curing process ensures product quality stability. The entire device has a reasonable structure and is easy to operate, effectively realizing the high-value utilization of phosphogypsum industrial waste, and possesses good industrial application prospects and economic benefits.

[0041] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although the utility model has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of this utility model.

Claims

1. A device for preparing phosphogypsum-based foaming materials, characterized in that: The apparatus for preparing phosphogypsum-based foamed material includes a raw material pretreatment system, a foaming preparation system, a molding system, and a curing system. The raw material pretreatment system includes a phosphogypsum storage silo (1), a screw feeder (2), a vibrating screen (3), a rotary dryer (4), and a weighing feeder (5) connected in sequence. The phosphogypsum is metered by the weighing feeder (5) and then enters a high-speed mixing foaming machine (6). The foaming preparation system includes a high-speed stirring foaming machine (6), a steam generator (7), and a foaming agent metering tank (8). The foaming agent metering tank (8) is connected to the foaming agent inlet of the high-speed stirring foaming machine (6) through a pipeline and a metering pump. The high-speed stirring foaming machine (6) is equipped with an annular steam distribution ring. The steam generator (7) is connected to the steam distribution ring through a pipeline. The molding system includes a continuous casting device (9) and a vibration leveling device (10); The curing system includes a tunnel curing kiln (11), a track conveying system (12), and a curing vehicle (13). The tunnel curing kiln (11) is equipped with a track conveying system (12), and the curing vehicle (13) carries the product and moves it in the kiln through the track conveying system (12).

2. The apparatus for preparing phosphogypsum-based foamed material according to claim 1, characterized in that: The high-speed stirring foaming machine (6) includes a stirring tank (61), a main stirring shaft (62), and an adjustable angle blade assembly (63). The main stirring shaft (62) is rotatably connected to the central axis of the stirring tank (61), and the adjustable angle blade assembly (63) is fixedly connected to the outer periphery of the main stirring shaft (62).

3. The apparatus for preparing phosphogypsum-based foamed material according to claim 2, characterized in that: An annular steam distribution ring (64) is fixedly connected above the adjustable angle blade assembly (63) on the inner wall of the mixing tank (61).

4. The apparatus for preparing phosphogypsum-based foamed material according to claim 1, characterized in that: The foaming agent inlet is located in the tangential direction of the mixing tank (61).

5. The apparatus for preparing phosphogypsum-based foamed material according to claim 1, characterized in that: The continuous casting device (9) includes a casting hopper, an adjustable casting nozzle, a forming conveyor belt, and a side forming plate. The lower end of the casting hopper is fixedly connected to the adjustable casting nozzle, and a forming conveyor belt is provided below the adjustable casting nozzle. The inner sides of both sides of the forming conveyor belt are fixedly connected to the side forming plate, which controls the product width through hydraulic adjustment.

6. The apparatus for preparing phosphogypsum-based foamed material according to claim 5, characterized in that: The vibration leveling device (10) is positioned above the forming conveyor belt.

7. The apparatus for preparing phosphogypsum-based foamed material according to claim 1, characterized in that: The tunnel-type curing kiln (11) is divided into four temperature control zones along its length: a preheating zone, a heating zone, a constant temperature zone, and a cooling zone.

8. The apparatus for preparing phosphogypsum-based foamed material according to claim 7, characterized in that: The tunnel-type curing kiln (11) has steam pipes arranged along its length, and the top of the kiln body is equipped with a dehumidification port and a regulating valve.

9. The apparatus for preparing phosphogypsum-based foamed material according to claim 1, characterized in that: The rotary dryer (4) is equipped with a lifting plate inside the cylinder.

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